1. Technical Field
The present invention relates to a tongue assembly for use in a vehicle seat belt system for restraining movement of an occupant of a vehicle.
2. Description of the Prior Art
A known vehicle seat belt system is a three-point continuous loop seat belt system. A three-point continuous loop seat belt system includes a seat belt retractor and a length of belt webbing. The belt webbing extends from the retractor through a D-ring fixed to the vehicle and then down to an anchor point near the vehicle floor. A tongue assembly is slidable along the belt webbing. To use the seat belt system, a vehicle occupant grasps the tongue assembly and inserts it into a buckle. When the tongue assembly is fastened in the buckle, a portion of the belt webbing extends across the lap of the vehicle occupant and a portion of the belt webbing extends diagonally across the torso of the vehicle occupant.
A three-point continuous loop seat belt system may sometimes be used to secure a child seat in the vehicle seat. In this case, it is necessary to fix the length of the lap portion of the belt webbing, so that the child seat can not move relative to the vehicle seat. Thus, it is desirable that a tongue assembly for a three-point continuous loop seat belt system be able to block movement of the belt webbing through the tongue assembly when the tongue assembly is fastened in the buckle. It is also desirable that the belt webbing run relatively freely through the tongue assembly when the tongue assembly is adjacent the D-ring, so that the belt webbing can be wound on the retractor.